Australian owned solar technology makes storage breakthrough

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Australian-owned solar thermal company says additional of molten salt storage makes technology “competitive” and able to provide power 24/7.

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Novatec Solar – a company majority owned by Australia’s Transfield Holdings – has commissioned a solar thermal energy demonstration plant in Spain that is based on a new type of molten salt storage technology.

The Germany-based Novatec Solar says the new plant uses a process called direct molten salt or DMS technology – where inorganic salts are used as a heat transfer fluid rather than oils.

novatec_solar_puerto_errado_2_aerial_view_websiteThis means that the plant can operate at temperatures well above 500°C, resulting in a significant increase in power yield. This means that costs are lowered significantly and the solar plants can act as baseload generators if required.

Andreas Wittke, CEO of Novatec Solar, which is 85 per cent owned by Australia’s Transfield Holdings, says this means that the technology will be able to operate on a “commercial” basis.

 

“The successful commissioning and the initial results of the DMS demo plant have confirmed our expectations of the technology,” he said in a statement.

“We are delighted that we can now offer solar thermal power plants with molten salt technology and thermal storage on a commercial basis.”

The use of DMS technology is being used at the 110MW Crescent Dunes power tower unit nearing completion in Nevada, which will be the largest solar thermal plant with storage in the world.

120628_novatec_solar_solar_boiler_liddell_8Novatec Solar will use DMS with its linear Fresnel technology, which has been deployed as a demonstration “solar booster” at the Liddell coal generator in NSW (pictured), and is being mooted for a renewables-based replacement for the Collinsville coal fired power station in Queensland.

Wittke says that the demonstration plant in southern Spain that features this new technology will be used to simulate a large number of different operating conditions to help develop the next generation of solar thermal power plants.

The storage capability means that the thermal energy can  either be directly converted into electrical power or be stored in large molten salt tanks during periods of low demand.

This stored energy can be kept in reserve for times when production is low, for example when the sky is overcast. Solar thermal power plants with storage systems can supply electricity as and when required, which helps to ensure grid stability.

The molten salt technology was developed by BASF for the Fresnel collector technology, which uses flat glass reflectors rather than parabolic trough collectors.

The reflectors concentrate direct sunlight onto a receiver, through which the molten salt is pumped. This has the effect of heating the salt to temperatures in excess of 500°C.

“Our knowledge of salt chemistry and the new technology concepts are contributing to a significant improvement in the efficiency of solar thermal power plants,” says Kerstin Dünnwald, Head of Business Management for Inorganic Chemicals at BASF.

The DMS demonstration collector project is supported by the German Federal Ministry for Economic Affairs and Energy (BMWi) following a decision by the German parliament.

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9 Comments
  1. JohnRD 5 years ago

    What has this got to offer that isn’t already there in solar tower technology?
    I think at this stage in the clean up process solar thermal with salt storage should be designed to supply power during the late afternoon early evening peak rather than 24/7.

    • Peter Thomson 5 years ago

      Good question – the concentrated solar is more localised than with a tower, so possibly less bird kills? Also the low profile of troughs reduce glare problems.
      But then, troughs are generally less efficient and more expensive than towers for the same power output, so why wouldn’t you use a tower?
      I wonder if they have found a salt which is liquid at ambient as well as 500C, because I can’t imagine how you would melt salts to start up such a large frozen system.

      • Nick Sharp 5 years ago

        … or re-melt in the event of a freeze, perish the thought. Na/K NO3 (60/40) MP around 221 deg C. I think there are mixes with lower MPs (using more expensive salts) but I doubt there are ambient MP ones, certainly not that can go up to near 600. Problem with long not very fat pipes of molten salt is the much higher ratio of surface area to volume, hence easier cooling. Some sort of thermal insulation at night needed?

        Must confess to being quite interested in CSIRO’s graphite storage idea. EVEN higher temps (~800?) than molten salt, and a solid state store at all times – nothing to melt; nothing in danger of setting.

        No silver bullet eh?!

        • Greg Churm 5 years ago

          In the BZE design the cold tank was at about 250C and the hot tank about 800C. They stored enough energy to run the plant flat out for 7.5 hours Strange that this sort of renewable energy seems to have fallen out of favour with commentators but I think it is an essential part of the mix. There would be plenty of marginal farms out west where the farmer would be only too happy to rent some land for this purpose.

          • Nick Sharp 5 years ago

            Actually, Greg, BZE suggested no less than 290 for the ‘cold’ salt (I guess to stay well away from 221 when the salt mix sets!) but cannot go much beyond 565 for the hot tank, as the nitrate salts start to dissociate into nitrites and oxygen. But yes, this approach allows storage of enough energy that supply can usually continue throughout the night.

  2. Ken Fabian 5 years ago

    “Novatec Solar will use DMS with its linear Fresnel technology…”

    Is this the same linear Fresnel technology as invented by David Mills, developed by Solar Heat and Power P/L, to become Ausra Ltd, to be purchased by Areva, and then unceremoniously abandoned when Areva did major cost cutting? What happened to the rights to this technology when Areva dumped it? Sold on with encouragement for others (Novatec perhaps) to achieve what they could not? Or put on shelf with threats of lawsuits to any who dare do anything similar?

    It’s a great disappointment when good ideas get abandoned, when it’s not because they don’t work but because of other factors, both internal (financing, management) and external (government energy policy shifts, market changes). I realise that solar thermal has come to look less attractive compared to PV with it’s dramatic cost reductions, but it’s capacity to include energy storage is very valuable. This will become ever more apparent as low emissions energy comes to be more than a minority element of an energy supply network. An innovative approach to thermal storage was an important element of David Mills/Ausra’s plans and intentions.

  3. David McKay 5 years ago

    This is not the technology developed by David Mills, but similar. Fresnel Technology has been around for a long time. Novatec use a larger number of smaller Reflectors & tend to have a simgle tube Boiler vs multi-tube Boilers in the Solar Heat & Power, etc systems. Interstingly, SHP had also developed Heliostats for use with tower technology. They completed 2 projects in Ausytralia & one in Germany using this technology.
    The whole SHP/AUSRA/AREVA was one sorry saga.
    SHP was a tightly run start-up. When it moved to California as AUSRA, the restraint continued for a while, however, cash was spent on speculative items like 2 x second hand steam turbines that were eventually sold for scrap. The investors insisted on replacing the original Australian CEO with a US CEO from “big power”. The entrepreneurship was gone & a large amount of investors funds was spent for nil market success. What followed was 4 CEOs in 8 years – hardly a formula for stability.
    It is my opinion that AREVA eventually decided to walk away as they could not get the cost structure to work. I don’t think this had anything much to do with the technology, more to do with a huge nuclear business taking over a struggling operation that really needed to be run as a very lean business. Siemens was a similar case with Solel.
    All these technologies can be complementary. PV is low cost but no viable storage, (yet) CSP is higher cost but has storage, at even higher cost.
    I believe AREVA will just wrap up its outstanding projects (in some form) & close up shop. I don’t believe they would want to expend more cash fighting battles over design/technology infringements. Might be wrong, but from the financials for AREVA generally, I don’t think they would waste their money.
    Everybody blames the market or the technology, etc, however, I firmly believe it is all about execution perfection along with first having a viable business case.

    • Ken Fabian 5 years ago

      Thanks for this David. The essential ingredients of trough CSP did look similar to me.

      We rarely get to follow the ongoing activities of the great many great innovations that do manage to come to public attention and most seem to disappear without a trace. I do wonder if it’s possible to do better in giving new life to the ones that fail for reasons other than the technologies. Sliver Cells is another that comes to mind that appeared to have great promise, but failed in the implementation and commercialisation. Origin Energy left the intellectual property with Transform Solar but if they even exist anymore is a question.

    • Mike Shurtleff 5 years ago

      “PV is low cost but no viable storage, (yet)”
      I keep reading comments like this. They are out of date. SolarCity is selling Tesla lithium battery packs to homes, businesses, and utilities for PV energy storage. Sunpower has an agreement with KB Homes and is doing the same thing. They are already running pilot tests in Australia and you should be able to purchase next year, here:
      http://cleantechnica.com/2014/08/06/sunpower-forsees-commercial-solar-energy-storage-2015/ – August 2014
      “SunPower Foresees Commercial Energy Storage In 2015”

      “CSP is higher cost but has storage, at even higher cost.” Bingo! That is the problem. CSP uses more complex structures and, as a result, it costs more. Installing PV is like installing CSP heliostats, except you are mostly done at that point for PV and you probably aren’t half done for CSP. You still have plumbing and a thermal plant to build. This says to me it will always be higher cost.

      Add to that the flaming bird problem for CSP (especially towers) and the glare problem (mostly towers) and you have a dead technology walking. It’s supposed to be environmentally friendly, but then it turns out not to be. That’s a hard sell.

      Sorry, I think the CSP work that’s been done is awesome. I think it’s too bad it is not panning out. I’m just trying to look at renewable technologies realistically. Looks to me like CSP has lost in the market to PV and I don’t see this changing. CSP efforts in the Middle East will be interesting to watch.

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